diff --git a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.integration.test.tsx b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.integration.test.tsx
index 78280e32eed..51dfe9fda90 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.integration.test.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.integration.test.tsx
@@ -24,12 +24,18 @@ describe("useScopedDailyActivityRange wiring", () => {
     );
     global.fetch = mockFetch;
 
-    renderHook(() => useScopedDailyActivityRange("sk-token", { userId: "u1", apiKey: "hash-abc" }));
+    const activity = {
+      dateValue: { from: new Date(2026, 7, 1), to: new Date(2026, 7, 10) },
+      onDateChange: vi.fn(),
+    };
+    renderHook(() => useScopedDailyActivityRange("sk-token", { userId: "u1", apiKey: "hash-abc" }, activity));
 
     await waitFor(() => expect(mockFetch).toHaveBeenCalled());
 
     const url = String(mockFetch.mock.calls[0][0]);
     expect(url).toContain("user_id=u1");
     expect(url).toContain("api_key=hash-abc");
+    expect(url).toContain("start_date=2026-08-01");
+    expect(url).toContain("end_date=2026-08-10");
   });
 });
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.ts b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.ts
index 234144f4423..3435b57dbc8 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.ts
+++ b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/useDailyActivityRange.ts
@@ -37,7 +37,9 @@ export interface DailyActivityScope {
   apiKey?: string | null;
 }
 
-export const useActivityDateRange = (): Pick<DailyActivityRange, "dateValue" | "onDateChange"> => {
+export type ActivityDateRange = Pick<DailyActivityRange, "dateValue" | "onDateChange">;
+
+export const useActivityDateRange = (): ActivityDateRange => {
   const initialFrom = useMemo(() => new Date(new Date().getTime() - THIRTY_DAYS_MS), []);
   const initialTo = useMemo(() => new Date(), []);
   const [dateValue, setDateValue] = useState<DateRange>({ from: initialFrom, to: initialTo });
@@ -47,9 +49,8 @@ export const useActivityDateRange = (): Pick<DailyActivityRange, "dateValue" | "
 export const useScopedDailyActivityRange = (
   accessToken: string | null,
   scope: DailyActivityScope,
+  { dateValue, onDateChange }: ActivityDateRange,
 ): DailyActivityRange => {
-  const { dateValue, onDateChange } = useActivityDateRange();
-
   const startTime = dateValue.from ?? null;
   const endTime = dateValue.to ?? null;
   const { userId, apiKey = null } = scope;
@@ -82,7 +83,7 @@ export const useDailyActivityRange = (
   accessToken: string | null,
   userId: string | null,
   userRole: string,
-): DailyActivityRange =>
-  useScopedDailyActivityRange(accessToken, {
-    userId: spendScopeUserId(userRole, userId),
-  });
+): DailyActivityRange => {
+  const dateRange = useActivityDateRange();
+  return useScopedDailyActivityRange(accessToken, { userId: spendScopeUserId(userRole, userId) }, dateRange);
+};
diff --git a/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.integration.test.tsx b/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.integration.test.tsx
index 69d2f1b896b..8cfd9d1941e 100644
--- a/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.integration.test.tsx
+++ b/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.integration.test.tsx
@@ -75,7 +75,11 @@ describe("KeyAutoRouterUsageTab", () => {
   });
 
   it("renders this key's spend, baseline, savings and per-router filter", async () => {
-    renderWithProviders(<KeyAutoRouterUsageTab accessToken="test-token" keyToken="key-hash-1" />);
+    const activity = {
+      dateValue: { from: new Date(2025, 0, 1), to: new Date(2025, 0, 31) },
+      onDateChange: vi.fn(),
+    };
+    renderWithProviders(<KeyAutoRouterUsageTab accessToken="test-token" keyToken="key-hash-1" activity={activity} />);
 
     expect(await screen.findByText("$8.75")).toBeInTheDocument();
     expect(screen.getByText("Actual auto-router spend")).toBeInTheDocument();
@@ -88,5 +92,7 @@ describe("KeyAutoRouterUsageTab", () => {
 
     const benchmarkUrl = new URL(requestedUrls().find((url) => url.includes("/auto_router/benchmarks")) ?? "");
     expect(benchmarkUrl.searchParams.get("api_key")).toBe("key-hash-1");
+    expect(benchmarkUrl.searchParams.get("start_date")).toBe("2025-01-01");
+    expect(benchmarkUrl.searchParams.get("end_date")).toBe("2025-01-31");
   });
 });
diff --git a/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.tsx b/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.tsx
index a2a7b9079a5..9e1cee1ec2e 100644
--- a/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.tsx
+++ b/ui/litellm-dashboard/src/components/templates/KeyAutoRouterUsageTab.tsx
@@ -3,15 +3,16 @@
 import React from "react";
 
 import { AutoRouterUsageView } from "@/app/(dashboard)/cost-optimization/_components/AutoRouterBenchmarksTab";
-import { useActivityDateRange } from "@/app/(dashboard)/cost-optimization/_components/useDailyActivityRange";
+import type { ActivityDateRange } from "@/app/(dashboard)/cost-optimization/_components/useDailyActivityRange";
 
 interface KeyAutoRouterUsageTabProps {
   accessToken: string | null;
   keyToken: string;
+  activity: ActivityDateRange;
 }
 
-const KeyAutoRouterUsageTab: React.FC<KeyAutoRouterUsageTabProps> = ({ accessToken, keyToken }) => (
-  <AutoRouterUsageView accessToken={accessToken} activity={useActivityDateRange()} apiKey={keyToken} />
+const KeyAutoRouterUsageTab: React.FC<KeyAutoRouterUsageTabProps> = ({ accessToken, keyToken, activity }) => (
+  <AutoRouterUsageView accessToken={accessToken} activity={activity} apiKey={keyToken} />
 );
 
 export default KeyAutoRouterUsageTab;
diff --git a/ui/litellm-dashboard/src/components/templates/KeySavingsTab.integration.test.tsx b/ui/litellm-dashboard/src/components/templates/KeySavingsTab.integration.test.tsx
index 6c7d65ee566..385c3967d02 100644
--- a/ui/litellm-dashboard/src/components/templates/KeySavingsTab.integration.test.tsx
+++ b/ui/litellm-dashboard/src/components/templates/KeySavingsTab.integration.test.tsx
@@ -46,6 +46,11 @@ const mockActivity = (
 
 const scopedRange = () => vi.spyOn(useScopedDailyActivityRangeModule, "useScopedDailyActivityRange");
 
+const activity = {
+  dateValue: { from: new Date(2025, 0, 1), to: new Date(2025, 0, 31) },
+  onDateChange: vi.fn(),
+};
+
 const renderTab = (props: Partial<React.ComponentProps<typeof KeySavingsTab>> = {}) =>
   render(
     <KeySavingsTab
@@ -53,6 +58,7 @@ const renderTab = (props: Partial<React.ComponentProps<typeof KeySavingsTab>> =
       keyToken="key-abc123"
       userId="user-123"
       userRole="Internal User"
+      activity={activity}
       {...props}
     />,
   );
@@ -114,7 +120,7 @@ describe("KeySavingsTab", () => {
 
     renderTab({ userId: "user-456", userRole: "Internal User" });
 
-    expect(hook).toHaveBeenCalledWith("test-token", { userId: "user-456", apiKey: "key-abc123" });
+    expect(hook).toHaveBeenCalledWith("test-token", { userId: "user-456", apiKey: "key-abc123" }, activity);
     expect(screen.getByTestId("key-savings-scope-note")).toHaveTextContent("Showing your own requests");
   });
 
@@ -123,7 +129,7 @@ describe("KeySavingsTab", () => {
 
     renderTab({ userId: "admin-123", userRole: "Admin" });
 
-    expect(hook).toHaveBeenCalledWith("test-token", { userId: null, apiKey: "key-abc123" });
+    expect(hook).toHaveBeenCalledWith("test-token", { userId: null, apiKey: "key-abc123" }, activity);
     expect(screen.queryByTestId("key-savings-scope-note")).not.toBeInTheDocument();
   });
 
@@ -132,7 +138,7 @@ describe("KeySavingsTab", () => {
 
     renderTab({ userId: "org-admin-1", userRole: "Org Admin" });
 
-    expect(hook).toHaveBeenCalledWith("test-token", { userId: "org-admin-1", apiKey: "key-abc123" });
+    expect(hook).toHaveBeenCalledWith("test-token", { userId: "org-admin-1", apiKey: "key-abc123" }, activity);
     expect(screen.getByTestId("key-savings-scope-note")).toHaveTextContent("Showing your own requests");
   });
 });
diff --git a/ui/litellm-dashboard/src/components/templates/KeySavingsTab.tsx b/ui/litellm-dashboard/src/components/templates/KeySavingsTab.tsx
index 967c3c7eff0..c33529eb042 100644
--- a/ui/litellm-dashboard/src/components/templates/KeySavingsTab.tsx
+++ b/ui/litellm-dashboard/src/components/templates/KeySavingsTab.tsx
@@ -22,7 +22,10 @@ import {
   usd,
   withStartAnchor,
 } from "@/app/(dashboard)/cost-optimization/_components/costOptimizationUtils";
-import { useScopedDailyActivityRange } from "@/app/(dashboard)/cost-optimization/_components/useDailyActivityRange";
+import {
+  useScopedDailyActivityRange,
+  type ActivityDateRange,
+} from "@/app/(dashboard)/cost-optimization/_components/useDailyActivityRange";
 
 interface KeySavingsTabProps {
   accessToken: string | null;
@@ -30,19 +33,19 @@ interface KeySavingsTabProps {
   keyToken: string;
   userId: string | null;
   userRole: string;
+  activity: ActivityDateRange;
 }
 
-const KeySavingsTab: React.FC<KeySavingsTabProps> = ({ accessToken, keyToken, userId, userRole }) => {
+const KeySavingsTab: React.FC<KeySavingsTabProps> = ({ accessToken, keyToken, userId, userRole, activity }) => {
   // Proxy admins read the whole key. For anyone else the endpoint applies the caller's own user_id
   // alongside the key filter, so the figures cover only that viewer's requests on this key -- said
   // plainly in the scope note below rather than left to be misread as the key's total.
   const readsWholeKey = hasProxyWideSpendView(userRole);
-  const activity = useScopedDailyActivityRange(accessToken, {
-    userId: spendScopeUserId(userRole, userId),
-    apiKey: keyToken,
-  });
-
-  const { dateValue, onDateChange, results, loading, isFetchingMore } = activity;
+  const { dateValue, onDateChange, results, loading, isFetchingMore } = useScopedDailyActivityRange(
+    accessToken,
+    { userId: spendScopeUserId(userRole, userId), apiKey: keyToken },
+    activity,
+  );
   const startTime = dateValue.from ?? null;
   const endTime = dateValue.to ?? null;
 
diff --git a/ui/litellm-dashboard/src/components/templates/key_info_view.test.tsx b/ui/litellm-dashboard/src/components/templates/key_info_view.test.tsx
index feee1cee9e6..175e57f2f44 100644
--- a/ui/litellm-dashboard/src/components/templates/key_info_view.test.tsx
+++ b/ui/litellm-dashboard/src/components/templates/key_info_view.test.tsx
@@ -26,8 +26,28 @@ vi.mock("./key_edit_view", () => ({
   },
 }));
 
+import type { ActivityDateRange } from "@/app/(dashboard)/cost-optimization/_components/useDailyActivityRange";
+
+const AnalyticsDateControl = ({ activity, keyToken }: { activity: ActivityDateRange; keyToken: string }) => (
+  <div>
+    <span data-testid="key-auto-router-usage">{keyToken}</span>
+    <output aria-label="Selected dates">{activity.dateValue.from?.toISOString()}</output>
+    {[1, 10].map((day) => (
+      <button
+        key={day}
+        onClick={() => activity.onDateChange({ from: new Date(Date.UTC(2026, 7, day)), to: new Date(2026, 7, 20) })}
+      >
+        Select August {day}
+      </button>
+    ))}
+  </div>
+);
+
 vi.mock("./KeyAutoRouterUsageTab", () => ({
-  default: ({ keyToken }: { keyToken: string }) => <div data-testid="key-auto-router-usage">{keyToken}</div>,
+  default: (props: React.ComponentProps<typeof AnalyticsDateControl>) => <AnalyticsDateControl {...props} />,
+}));
+vi.mock("./KeySavingsTab", () => ({
+  default: (props: React.ComponentProps<typeof AnalyticsDateControl>) => <AnalyticsDateControl {...props} />,
 }));
 
 vi.mock("@/app/(dashboard)/hooks/useTeams", () => ({
@@ -189,6 +209,22 @@ describe("KeyInfoView", () => {
     expect(screen.getByTestId("key-auto-router-usage")).toHaveTextContent("test-token-123");
   });
 
+  it("preserves dates in both directions across unmounted analytics panels", async () => {
+    vi.mocked(useAuthorized).mockReturnValue({ ...baseUseAuthorizedMock, userRole: "Admin" });
+    renderWithProviders(<KeyInfoView keyData={MOCK_KEY_DATA} onClose={() => {}} keyId="test-key-id" teams={[]} />);
+
+    expect(screen.queryByLabelText("Selected dates")).not.toBeInTheDocument();
+    await userEvent.click(screen.getByRole("tab", { name: "Savings" }));
+    await userEvent.click(screen.getByRole("button", { name: "Select August 1" }));
+    await userEvent.click(screen.getByRole("tab", { name: "Auto-router usage" }));
+    expect(screen.getByLabelText("Selected dates")).toHaveTextContent("2026-08-01T00:00:00.000Z");
+    await userEvent.click(screen.getByRole("button", { name: "Select August 10" }));
+    await userEvent.click(screen.getByRole("tab", { name: "Settings" }));
+    expect(screen.queryByLabelText("Selected dates")).not.toBeInTheDocument();
+    await userEvent.click(screen.getByRole("tab", { name: "Savings" }));
+    expect(screen.getByLabelText("Selected dates")).toHaveTextContent("2026-08-10T00:00:00.000Z");
+  });
+
   it("does not offer the admin-only auto-router usage tab to an internal user", () => {
     vi.mocked(useAuthorized).mockReturnValue({ ...baseUseAuthorizedMock, userRole: "Internal User" });
     renderWithProviders(<KeyInfoView keyData={MOCK_KEY_DATA} onClose={() => {}} keyId="test-key-id" teams={[]} />);
diff --git a/ui/litellm-dashboard/src/components/templates/key_info_view.tsx b/ui/litellm-dashboard/src/components/templates/key_info_view.tsx
index 86bbfd73410..f5c682a2ee0 100644
--- a/ui/litellm-dashboard/src/components/templates/key_info_view.tsx
+++ b/ui/litellm-dashboard/src/components/templates/key_info_view.tsx
@@ -17,6 +17,7 @@ import { BadgeLink } from "@/components/shared/BadgeLink";
 import { KeyInfoHeader } from "./KeyInfoHeader";
 import KeySavingsTab from "./KeySavingsTab";
 import KeyAutoRouterUsageTab from "./KeyAutoRouterUsageTab";
+import { useActivityDateRange } from "@/app/(dashboard)/cost-optimization/_components/useDailyActivityRange";
 import { useEffect, useState } from "react";
 import {
   hasProxyWideSpendView,
@@ -87,6 +88,7 @@ export default function KeyInfoView({
   backButtonText = "Back to Keys",
 }: KeyInfoViewProps) {
   const { accessToken, userId: userID, userRole, premiumUser } = useAuthorized();
+  const activityDateRange = useActivityDateRange();
   const queryClient = useQueryClient();
   const canEditGuardrails = premiumUser || (userRole != null && rolesWithWriteAccess.includes(userRole));
   const { teams: teamsData } = useTeams();
@@ -772,12 +774,17 @@ export default function KeyInfoView({
               keyToken={currentKeyData.token}
               userId={userID}
               userRole={userRole}
+              activity={activityDateRange}
             />
           </TabsContent>
 
           {hasProxyWideSpendView(userRole) && (
             <TabsContent value="auto-router-usage">
-              <KeyAutoRouterUsageTab accessToken={accessToken} keyToken={currentKeyData.token} />
+              <KeyAutoRouterUsageTab
+                accessToken={accessToken}
+                keyToken={currentKeyData.token}
+                activity={activityDateRange}
+              />
             </TabsContent>
           )}